In an isobaric process of an ideal gas, the ratio of heat supplied and work done by the system $\left(\frac{\mathrm{Q}}{\mathrm{W}}\right)$ is $\left[\frac{\mathrm{C}_{\mathrm{P}}}{\mathrm{C}_{\mathrm{V}}}=\gamma\right]$

In an isobaric process, pressure remains constant. The heat supplied to the gas is $Q = nC_P\Delta T$, while the work done by the system is $W = P\Delta V = nR\Delta T$.

The ratio simplifies to $\frac{Q}{W} = \frac{C_P}{R}$. Using Mayer's relation $C_P - C_V = R$ and the definition $\gamma = \frac{C_P}{C_V}$, we obtain:

$\frac{Q}{W} = \frac{\gamma}{\gamma - 1}$

Final answer: $\boxed{\text{C}}$